Robotic surgery guided by 3-D ultrasound scanner
7 November 2006
Durham, N.C. USA. Duke University engineers have shown
that a three-dimensional ultrasound scanner they developed can successfully
guide a surgical robot.
In their demonstration, the researchers used 3-D
ultrasound images to pinpoint in real time the exact location of targets in
a simulated surgical procedure. That spatial information then guided a
robotically controlled surgical instrument right to its mark.
could find application in various medical settings, according to the
researchers. They said the scanner ultimately might enable surgeries to be
performed without surgeons, a capability that could prove valuable in space
stations or other remote locations.
"It's the first time, to our
knowledge, that anyone has used the information in a 3-D ultrasound scan to
actually guide a robot," said Stephen Smith, professor of biomedical
engineering at Duke's Pratt School of Engineering.
Smith and Eric Pua, a
Pratt graduate student who participated in the research, reported the
findings in the cover article of the November 2006 issue of the journal IEEE
Transactions on Ultrasonics, Ferroelectrics and Frequency Control
(www.ieee-uffc.org/tr/covers/2006toc.htm#nov06). The work was supported
by the National Institutes of Health and the National Science Foundation.
The scanner could be coupled to the surgeon-operated robots that are being
increasingly used for performing minimally invasive "laparoscopic" surgeries
on the heart or other organs, Smith said. In such operations, surgeons work
through tiny "keyhole" incisions, and the new scanner would provide surgeons
a more realistic view of the organ they are working on.
technology is available," Smith said. "We just need to make the connections
between the ultrasound scanner and the robots now in use by surgeons. There
are no technological barriers to doing that right away."
applications, surgeons could use the 3-D scanner to spot potential tumours
in real time during biopsy procedures, making a diagnosis of cancer harder
to miss, the engineers said. Physicians today must rely on still images,
such as CT scans, of a patients' organs captured prior to biopsy to locate
lesions suspected to be cancer.
As artificial intelligence technology
improves in the coming decades, the scanner might even be able to guide
surgical robots without the help of a surgeon, the researchers said.
3-D ultrasound probe has yet to be tested in human patients, Smith said, but
he added that his team believes the technology is ready for clinical trials.
The Duke team in 1987 developed the first-ever 3-D ultrasound scanner for
imaging the heart in real time from outside the body. As technology enabled
ever smaller ultrasound arrays, the researchers engineered probes that could
fit inside catheters threaded through blood vessels to view the vasculature
and heart from the inside.
Earlier this year, the team reported another
advance: a 3-D ultrasound device including 500 tiny cables and sensors
packed into a tube 12 millimetres in diameter — small enough to be inserted
through the incisions required for laparoscopic surgeries (see
http://www.pratt.duke.edu/news/?id=417). The researchers then showed
that the device can produce actual 3-D images of the beating hearts in
The team has since demonstrated that the scanner also can be used
to laparoscopically image other organs, including the spleen, liver and gall
In the current study, the researchers used the scanner to
identify coordinates denoting the precise location of an artificial lesion
inside a type of artificial organ, or "phantom," commonly used for testing
imaging technologies. The researchers then entered the coordinates into a
simple robot that controlled a biopsy needle, and the robot did the rest.
The researchers also have used the scanner to guide the biopsy robot toward
a designated target in the gall bladder of an animal that had died. (An
ultrasound video of the needle travelling toward and then precisely
puncturing the animal's organ can be downloaded at
"Once the robot takes over, it sends the needle to within about 1.5
millimeters of the center of the target," Smith said. "That's pretty good
The 3-D ultrasound scanner also has the advantage of seeing the
interior of organs, Smith said. Optical laparoscopes, in contrast, provide
surgeons only a view of organs' outer surfaces.
laparoscopic ultrasound has seen increased use as a surgical aide in
general, gynecological and urological procedures," Pua added. "Our results
show that the application of real-time 3-D ultrasound to these surgical
procedures may increase information available to the surgeon and serve as an
additional guidance tool."